Disk Brake on a Dominator

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laurentdom

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Dear All,

Since I have a powerful / vibration free (Thanks Jim!) Commando engine in my Featherbed chassis, front and rear brakes are a bit short of effectiveness, to say the least.

I consider fitting a Commando front disk brake, but I would like to keep the Dominator look, ie the headlamp and its lugs + the shrouds.

I heard that the last Featherbeds and the early Commando had "Dominator-looking" 7"3/8 yokes which would make it simpler to fit a disk brake than using my genuine 7" yokes and having to adapt a wheel + disk + caliper to that width.

Can someone confirm that those "Dominator-looking" 7"3/8 yokes exist and give me ideas about where to find them? (or ideas about other components to use)

Which change to the handling should I expect?

Many thanks

L.
 
One option would be to fit a Commando twin-leading-shoe brake into that full-width eight-inch Dominator hub--it will slide right in--and would be a big improvement over the stock front brake



Tim Kraakevik
kraakevik@voyager.net
 
laurentdom said:
Which change to the handling should I expect?
.

If you substitute the 7 & 3/8" forks for your 7" forks, you should expect no change in the handling whatsover ?
It was said the wider forks were simply to accomodate a wider front tyre, as was coming into use at that time.
The difference on dommis at the time was barely visible.

Ashman on this forum has what he says are Commando disk forks and yokes on his wideline.
Been using them quite some time.
Be interesting to see exactly what yokes they use...
 
I run the whole 74 Commando front end on my Wideline Featherbed, from steering bearings, yokes and complete front end, there was no moderforcation what so ever when I did this 33 years ago and is still on the bike to this day, except for the Grimaca front brake kit and Lansdown front end kit, most of my Featherbed has my old Commando parts on it, the bike handles as a Featherbed should.

Ashley
 
You mentioned that your fork tubes had the large nut at the bottom.
Which is not stock Commando, but earlier long roadholders.
Not that is makes much difference.
But it could mean the damping/springs are not stock either ?
 
I would avoid drum brakes at all costs. I use ceriani forks with two AP Lockheed calipers with the older asbestos pads on Suzuki discs. The brakes work with one finger and stop the bike like hitting a wall. At least with a disc, you have feel and control, and you can safely grab a handful. The self-servo effect which occurs with drum brakes is very dangerous to beginners who don't know how to set the brake up. I used a finger light 7R AJS drum in the front of my 500cc Triton. I still have the dislocated collar bone held in place with scar tissue.
If you find the discs are too much, you can always back them off with carbon pads. With a drum, if the leader heats up and sticks, you are off the bike.
 
Since the question here was about fitting a disk brake to a dommie, this above appears to be quite irrelevant. !?
BTW Since when did TLS brakes have more of a self-servo effect.

You also don't mention that your bike is a race bike, not a road bike...
 
If you do follow Tim's advice with the Commando 2LS brake, make sure you get the "improved" version. The early one would have trouble stopping a Vespa. On the prototypes, the front brake was very ineffective. We found that after a certain amount of force had been applied at the brake lever (rooughtly 60% of total travel), you could pull the lever all the way to the throttle twist-grip and get no additional braking. I did some brittle-lacquer tests on the original brakes and found significant distortion of the backplate as the force in the cable increased.

I'd left for the US before the revised/improved brake or the stiffener kits were introduced. We did a lot of testing of disk brakes, without much success. As I recall it, sliding calipers with a fixed pad opposite the piston-operated one hadn't appeared on the market, and management didn't want the big off-set of the right fork for a twin piston caliper, so they insisted on a sliding disk.

As you can imagine, getting a steel disk to slide on an aluminum spline or a set of dowel pins that was down around the axle, when force is applied close to the outside diameter of the disk at one point, proved to be impossible. We wasted a lot of development funds chasing it. It must have been a couple of years after I left when they finally got a disk brake that worked.
 
acotrel said:
I would avoid drum brakes at all costs. I use ceriani forks with two AP Lockheed calipers with the older asbestos pads on Suzuki discs. The brakes work with one finger and stop the bike like hitting a wall. At least with a disc, you have feel and control, and you can safely grab a handful. The self-servo effect which occurs with drum brakes is very dangerous to beginners who don't know how to set the brake up. I used a finger light 7R AJS drum in the front of my 500cc Triton. I still have the dislocated collar bone held in place with scar tissue.
If you find the discs are too much, you can always back them off with carbon pads. With a drum, if the leader heats up and sticks, you are off the bike.


Absolute b/s. I fitted a John Tickle 2ls front brake (which didn’t suffer the same problems as the Commando brake plate did.) to my race Atlas, took the bike to Joe Dunphy and had the brakes relined w.y.w. with green race linings in the front and brown in the rear. There was nobody who could outbrake me into any of the Brands Hatch corners, including the hairpin. This was in the 1970s so will not apply as much now with 6 pot calipers. When the front was cold I could lock up the front wheel, so i needed to respect it at all times.

http://otleysquashclub.org/when-gentlem ... greeves-at
 
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